The "temporal abominations" (AUDIO: The Abyss) usually referred to only as "abominations," were the creations of the Barber-Surgeon altering creatures from the Time Vortex. When he was erased from history, his abominations were never created. (AUDIO: The Horror)
They were mistaken for mutations of spacetime, the Time Lords and the Daleks each thinking the other side was responsible for them. (AUDIO: The Abyss)
One weakened abomination tore through a squad of Raston Warrior Robots before finally being killed, and other abominations twisted Daleks through four dimensions. (AUDIO: The Mission)